Crystal Radio Kit From The 1970s

If you read the December 1970 issue of Mechanix Illustrated, you’d be treated to [Len Buckwalter]’s crystal radio build. He called out Modern Radio Labs as the supplier for parts. That company, run by [Elmer Osterhoudt], got so many inquiries that he produced a kit, the #74 crystal set. [Michael Simpson] found an unopened kit on eBay and — after a bidding war, took possession of the kit. The kit looked totally untouched. The crystal detector was still in the box, and there were period-appropriate newspaper wrappings.

The kit itself isn’t that remarkable, but it is a classic. An oatmeal box serves as a coil form. There’s a capacitor, a crystal detector, and headphones. The original cost of the parts was $7, but we imagine the eBay auction exceeded that by a large amount.

If the name [Len Buckwalter] sounds familiar, he was quite prolific in magazines like Electronics Illustrated and also wrote several books about transistors. [Michael] also shows off his innovative coil winder made from plastic cups and a coat hanger.

We’d love to find some old kits like this, although, from one way of thinking, it is almost a shame to build them after all these years. With an added audio amplifier and fiddling with the cat whisker, it sounded just fine.

If you don’t like oatmeal, you could fire up the 3D printer. While the basic circuit is simple, you can make it more complex if you like.

19 thoughts on “Crystal Radio Kit From The 1970s

    1. Thank you for this link, too. It did exceed my expectations. There are some quite historical correct, high-quality detector radios being shown. Especially the vario-meter coils and the decoupling between antenna and detector stage is something that higher quality detector radios make use of. Vy73s.

      1. Speaking of, early amateurs and radio tinkerers did receive the distress messages of Titanic. That was possible with primtive sets because of the use of damped waves. Titanic did use morse telegraphy, but not CW yet.

  1. Nice article and a great kit find. I had a friend pas along to me a lot of MRL booklets and managed to hang onto a few of them. I still re-reading them from time to time.

    1. Yup. You can still hear one or two stations at night, though.

      On longwave, there were a few stations, too, still, last time I checked.

      The only real AM stations that remain are those being installed in museums, maybe.

      There’s Radio Eule, for example, a low-power AM transmitter, which airs from German Museum in Munich.
      It can be heard from outside the building, too.

      Other places around globe have similar installments, maybe.

    2. Speaking of younger generations..
      a) I think that we must introduce them to the hobby much earlier than back then.
      Not age 12 or 15, but roughly about age 6 onwards (maybe less).
      Nowadays generation grew up more fast, also because of our fast-paced society.
      b) Shortwave still exists. It’s a bit of work, but SSB signals from radio amateurs can still be received.
      An audion/regenerative receiver can receive SSB. A crystal radio with a BFO can do it, too.
      c) DRM, Digital Radio Mondiale, is an interesting field on its own. A direct-conversion reveiver+soundcard or an SDR can be used for reception (Dream software needed). Maybe something for the teenagers?

    3. Stick a fork in HAM.

      It’s been niche for decades.
      Was never widely popular, that was CB, which had it’s fad. They even made a ‘Convoy’ movie.

      Talking to someone on the other side of the planet rates a ‘meh’. Kids don’t even understand that it was something once.

      Maybe ‘moon bounce’ would rate ‘cool’. But only from the nerdiest. The more things change…

  2. The Remco RadioCraft was my crystal radio. Good pair of high impedance headphones, Salvaged flyback transformers for coil winding wire. Long piece of wire on a door spring into the oak tree, and from NJ could hear WABC 770 from across the river loud and clear.

    1. Across the river? It’s a clear channel station, you could receive it on Mars. I’ve received it in Washington DC on a $10 Chinese Suntek radio… during daylight. Doesn’t take away from the project though, good on ya!

Leave a Reply

Please be kind and respectful to help make the comments section excellent. (Comment Policy)

This site uses Akismet to reduce spam. Learn how your comment data is processed.